broadcast-tx.js

// Broadcast Zcash testnet transaction
const fetch = require('node-fetch');
const fs = require('fs');

async function broadcast() {
  // Read from file
  let txHex;
  if (fs.existsSync('testnet-tx.hex')) {
    txHex = fs.readFileSync('testnet-tx.hex', 'utf8').trim();
    console.log('📂 Loaded transaction from testnet-tx.hex');
  } else if (process.argv[2]) {
    txHex = process.argv[2];
    console.log('📋 Using transaction from command line');
  } else {
    console.error('❌ No transaction provided');
    console.log('\nUsage:');
    console.log('  node broadcast-tx.js [hex]');
    console.log('  or create testnet-tx.hex file');
    process.exit(1);
  }

  console.log('📤 Broadcasting transaction...');
  console.log('   Size:', txHex.length / 2, 'bytes');
  console.log('   First bytes:', txHex.slice(0, 32) + '...\n');

  try {
    // Try blockchair API
    console.log('🌐 Using Blockchair API...');
    const response = await fetch('https://api.blockchair.com/zcash/testnet/push/transaction', {
      method: 'POST',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
      body: `data=${txHex}`
    });

    const data = await response.json();

    if (data.data && data.data.transaction_hash) {
      const txid = data.data.transaction_hash;
      console.log('✅ SUCCESS! Transaction broadcast');
      console.log('');
      console.log('━'.repeat(60));
      console.log('🎉 TXID:', txid);
      console.log('━'.repeat(60));
      console.log('');
      console.log('🔍 View on explorer:');
      console.log(`   https://blockexplorer.one/zcash/testnet/tx/${txid}`);
      console.log('');
      console.log('📝 SAVE THIS TXID FOR BOUNTY SUBMISSION!');

      // Save TXID
      fs.writeFileSync('testnet-txid.txt', txid);
      console.log('💾 Saved to: testnet-txid.txt');

      return txid;
    } else {
      throw new Error(data.context?.error || 'Unknown error from API');
    }

  } catch (error) {
    console.error('❌ Broadcast failed:', error.message);
    console.log('');
    console.log('💡 Alternative methods:');
    console.log('');
    console.log('1. Use zcash-cli:');
    console.log(`   zcash-cli -testnet sendrawtransaction "${txHex}"`);
    console.log('');
    console.log('2. Use block explorer:');
    console.log('   https://blockexplorer.one/zcash/testnet (Broadcast tab)');
    console.log('   Paste the hex and submit');
    console.log('');
    console.log('3. If transaction is invalid, check:');
    console.log('   - UTXO is not already spent');
    console.log('   - Signature is correct');
    console.log('   - Fee is sufficient');

    process.exit(1);
  }
}

broadcast().catch(console.error);